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Implant failure
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- 2. •Introduction •Definitions •Predictors of implantsuccess or failure •Warning signs of implant failure •Criteria for implant success: •Implant quality scale: •Classifications of implant failures .Enhancing outcome in esthetic implant dentistry .implant maintenance •Conclusion •Bibliography Contents… 2
- 3. Implant dentistry iscurrently being practiced in an atmosphere of enthusiasm and optimism, because our knowledge and ability to provide service to our patients has expanded so greatly in such a short period. But Success cannot be guaranteed, what one can guarantee is to care, to do ones best and to be there to help in the rare instance that something goes wrong Introduction 3
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- 6. The surgeon’s tale ‘Theimplants were successfully integrated , but failed because of excess loads. or The Restorative Dentist’s tale ‘The implants were poorly integrated and so failed under normal masticatory loads.’ either way The Patient’s tale ‘My implants have failed!’ ………When implant fails……then………. 6
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- 8. IMPLANT FAILURE… It isdefined as total failure of the implant to fulfill its purpose (functional, esthetic or phonetic) because of mechanical or biological reasons. (Askary et al ID 1999 vol8 no2 173-183) Definitions … 8
- 9. Ailing implants: Those thatshow radiographic bone loss without inflammatory signs or mobility. Failing Implant: Characterized by progressive bone loss, signs of inflammation and no mobility. 9
- 10. Failed Implants: Those withprogressive bone loss, with clinical mobility and that which are not functioning in the intended sense. Surviving implants: Described by Alberktson, that applies to implants that are still in function but have been tested against the success criteria. 10
- 11. Predictors of implantsuccess or failure ( General dentistry 2005, 423-432) Positive factors Bone type (type 1and 2) Patient less than 60yrs old Experienced Clinician Mandibular placement Implant length > 8mm FPD with more than two implants Axial loading of implant Regular postoperative recalls Good oral hygiene 11
- 12. Negative factors Bone type(type 3 and 4) Low bone volume Patient more than 60yrs old Limited clinician experience Systemic diseases Auto-immune disease Chronic periodontitis Smoking and tobacco useUnresolved caries, endodontic lesions,frank pathology Maxillary, particularly posterior region Short implants (<7mm) Eccentric loading Inappropriate early clinical loading Bruxism and other parafunctional habits 12
- 13. Warning signs ofimplant failure (Askary et al ID 1999; vol 8; no2, 173-183) Connecting screw loosening Connecting screw fracture Gingival bleeding and enlargement Purulent exudates from large pockets Pain Fracture of prosthetic components Angular bone loss noted radiographically Long-standing infection and soft tissue sloughing during the healing period of first stage surgery 13
- 14. Criteria for implantsuccess: …The individual implant is immobile when tested clinically. …No radiographic evidence of peri-implant radiolucency …Bone loss no greater than 0.2 mm annually …Gingival inflammation amenable to treatment …Absence of symptoms of infection and pain …Absence of damage to adjacent teeth …Absence of parasthesia, anesthesia or violation of the mandibular canal or maxillary sinus …Should provide functional survival for 5 years in 90% of the cases and for 10 years in 85%. (Albrekfsson T. :int J. Oral Maxillofac Implants 1986; 1:11-25) 14
- 15. Implant qualityscale: The scalepresented for implant quality of health based on clinical evaluation was first suggested by James and was modified by Misch. This quality of health scale criteria, has to be place in the appropriate category, and then treat the implant accordingly. The prognosis also is related to the quality scale. 15
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- 17. ClassificationOf Implant failures …E.SRosenberg, J.P. Torosian and J. Slots …Abdel Salam El Askary, Roland Mefert and Terrence Griffin …Kees Heydenrijik, Henny JA Meijer, Wil A Van der et al … Marco Esposito, Jan Michael Hirsh, Ulf Lekholm et al …Sumiya Hobo, Eiji Ichida, Lily T Garcia 17
- 18. 1. Infectious Failure: …Clinicalsigns of infection with classic symptoms of inflammation …High plaque and gingival indices …Pocketing …Bleeding, Suppuration …Attachment loss …Radiographic peri-implant radiolucency …Presence of granulomatous tissue upon removal 2. Traumatic Failure: …Radiographic periimplant radiolucency …Mobility …Lack of granulomatous tissue upon removal …Lack of increased probing depths …Low plaque and gingival indices A) E.S Rosenberg, J.P. Torosian and J. Slots classified as : 18
- 19. B) Marco Esposito,Jan Michael Hirsh, Ulf Lekholm et al have classified oral implant failures according to the osseoi ntegration concept. 1)Biological Failures: •Early or primary (Before loading) •Late or secondary (After loading) 2)Mechanical failures: •Fracture of implants, connecting screws, bridge framework, coatings etc 3)Iatrogenic Failures • Improper implant angulation and alignment, nerve damage 4)Inadequate Patient adaptation • Phonetics, esthetics, psychological problems. 19
- 20. C) Kees Heydenrijik,Henny JA Meijer, Wil A Van der et al classified to occurrence in time as: 1) Early Failures: Causes attributed are: • Surgical trauma • Insufficient quantity or quality of bone • Premature loading of implant • Bacterial infection 2) Late Failures: Soon late failures: Implants failing during first year of loading. Overloading in relation to poor bone quality and insufficient bone volume. Delayed late failures: Implant failing in subsequent years. Progressive changes of the loading conditions in relation to bone quality, volume and peri -implantitis. 20
- 21. Swedish Team ( Branemarket al) U.C.L.A team (Beumer, Moy) 1. Loss of bone anchorage: a. Mucoperiosteal perforation b. Surgical trauma 2. Gingival problems: a. Proliferative gingivitis b. Fistula formation 3. Mechanical complications: a. Fracture of prosthesis, gold screws, abutment screws 1. Complications in Stage I surgery; 2. Complications in Stage II surgery: 3. Prosthetic complications: D) Sumiya Hobo, Eiji Ichida, Lily T Garcia enlisted various complications occurring in implants as: 21
- 22. E) Abdel Salamel Askary, Roland Meffert and terrence griffin … According to etiology Restorative factor Host factor Surgical factor Implant selection factor According to timing of failure Before stage II After stage II After restoration According to origin of infection Peri- implantitis (Infective process, bacterial origin) Retrograde peri-implantitis (Traumatic occlusion origin, non infective, forces off the long axis, premature or excessive loading) 22
- 23. According to failuremode Psychological problems Lack of osseointegration Unacceptable aesthetics Functional problems According to condition of failure Ailing Implant Failing Implant Failed Implant Surviving Im. According to supporting tissue type Soft tissue loss Bone loss Combination According to responsible personnel Dentist (Oral surgeon, Prosthodontist, Periodontist) Dental hygienist Laboratory Technician Patient 23
- 24. According to etiology Restorative factor Surgical factor Implant selectionfactor Host factor Medical status : Habits : Oral status 24
- 25. A. Hostfactors… MEDICAL STATUS…medical history is essential to rule out any of the following conditions or disorders. If yes… medical consultation Bone dieases CV Dieases Autoimmune Endocrine Pregnancy Hypertension MI Congestive heart failure SABE DM Thyroid disorders osteoporosis osteomalacia ? hyperparathyriodism fibrous dysplasia paget dz multiple myeloma ? osteomylitis sjogren syndrome ? SLE ? scleroderma ? HIV 25 Avoid to place implant in pregnancy …In all these conditions ,chances of success rate are poor but implant therapy … not contraindicated except few. Etiology : host factor
- 26. HABITS 1) Smoking: Significance •Causes alveolarvasoconstriction and decreased blood flow •Impaired wound healing due to compromised polymorphonuclear leucocytes function, increased platelet adhesiveness as well as vasoconstriction caused by nicotine. •Poor bone quality •In case of poor oral hygiene, smokers have 3 times more marginal bone loss then non-smokers Recommendations: 1.Obtain a smoking history 2.Advice on risks of periodontal breakdown 3.Advice on the prognosis .Smoking cessation Etiology : host factor 26
- 27. Parafunctional habits: Bruxism isthe multidirectional nonfunctional grinding of teeth. Clenching occurs in one direction (vertically). Bruxism is more aggressive. Attrition usually appears on the incisal edges of anterior teeth. Significance •Most common cause of implant bone loss or lack of rigid fixation during the first year after implant insertion. •Commonly manifests as connecting screw loosening because of overload. •Failures are higher in maxilla because of decrease in bone density. •Forces are in excess of normal physiologic masticatory load limit.( upto 1000 psi). Etiology : host factor 27
- 28. Prevention •Increased number ofimplants to be placed •Avoid cantilevers and occlusal contacts in lateral excursions •Use of occlusal splint which is relieved over the implant. •Use of wide diameter implant to provide greater surface area. Progressive bone loading and prosthetic design that improves the distribution of stresses throughout the implant system.( By Misch Etiology : host factor 28
- 29. Poor home care: ORALSTATUS: Suprabony connective tissue fibers are oriented parallel to the implant surface Susceptible to plaque accumulation and bacterial ingress Spontaneous loss of the perimucosal seal Chances of implant failure increases Etiology : host factor 29
- 30. Prevention •It is recommendedthat the patient be recalled frequently, preferably at a minimum of 3 months intervals. Periodontal indices, bleeding on probing and radiographic evaluation should be performed, using plastic tipped probes for checking pocket depths. •Soft tissue debridement should be performed by means of plastic curettes and plastic tips for ultrasonic scalers, and topical and systematic antimicrobial drugs should be used •Provide space beneath the superstructure to allow cleansing aids Etiology : host factor 30
- 31. IRRADIATION THERAPY Significance •Xerostomia •Susceptibility toinfection •Osteoradionecrosis •Endarteritis of vessels causes decrease in oxygen supply Prevention •Waiting period of 9-12 month between radiation therapy and implant treatment. •Hyperbaric oxygen therapy – 20 treatments of 90 min. each at 2 to 2.4atm before surgery. •Antibiotic regimen 3 days before (augmentin 500mg every 12 hrs). Etiology : host factor 31
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- 33. a) Off-axis placement(severe angulation)… Occlusal load lie at an angle Shear & tensile forces increases Chances of failure increases Problem… Due to… A) Alveolar process resorption B) Unexperienced surgeon C) Improper surgical stent Etiology : surgical factor 33
- 34. 1) Prerestoring theimplant position by grafting 2) To place the implant with an angulation. 3) To place angulated abutments. Solutions… Etiology : surgical factor 34
- 35. b) Lack ofinitial stability… Due to oversized osteotomy Gap develop between implant & bone Lack of osseointegration In an experimental investigation, gaps in the range of 0.25 mm around CPTi implants healed, but with less bone contact than the controls. When the gap size increased to 0.7mm-1.7mm, a thin soft tissue layer was found to develop around the implant. Etiology : surgical factor 35
- 36. Solution… Remove & reinsertthe larger size implant. if not possible remove insert HA graft material roll the implant moistened in blood & saline & in the particulate slurry until thin layer of slurry clings to it reinsert the implant Etiology : surgical factor 36
- 37. c) Improper healing& infection because of improper flap design… No single flap design is optimal for implant surgery. But improper flap design infection & bacterial ingress chances of failure increases Note: basic surgical procedure, flap design , blood supply, visibility,access, primary closure should be considered. Etiology : surgical factor 37
- 38. d) Overheating thebone and exerting too much pressure…… Etiology : surgical factor Excessive pressure Bone cell damage Bone loss Connective tissue interface formed Failure increases …Inverse relationship b/w speed & heat production …Recommended speed- 2000 rpm with graded series of drill size with external irrigation 38
- 39. Etiology : surgicalfactor 39
- 40. e) Placement ofimplant in immature bone grafted site… Etiology : surgical factor Minimum waiting period of grafted site…6-9 mth woven bone present before this period, which is fastest formed bone (partly mineralized &Unorganized) Lamellar bone ideal for implant prosthetic support Not suitable for implant-bone integration 40
- 41. f) Contamination ofimplant body before insertion… D/t …non-titanium instrument …by glove powder …by the operatory error By autoclaving the contaminated implant Bake the bacteria on implant surface Impossible for phagocytic cell to clean the surface No close adaptation to the bone Etiology : surgical factor 41
- 42. Etiology : surgicalfactor 42
- 43. According to etiology Restorative factor Host factor Surgical placement Implantselection factor… …Improper implant type in improper bone type… …length of the implant… …width of the implant… …number of the implant… …improper implant design… 43
- 44. Length of theimplant.. Misch proposed the range of 10mm-16mm length. The greater the crown implant ratio, the greater the amount of the force with any lateral force. This means that the implant with unfavorable crown implant ratio will be more influenced by lateral forces. Therefore, maximum implant length must be used for the greatest stability of the overlying prosthesis. The success rate is proportional to the implant length and the quantity and quality of available bone. The rate of failure can be expected to rise proportionately as the depth of the bone diminishes to less than 10mm. 44
- 45. Width of theimplant… Misch recommended that not less than 1 mm of bone surrounding the fixture labially and lingually is mandatory for the long term predictability of dental implants because it maintains enough bone thickness and blood supply. …it is advisable to use a large- diameter implant in accordance with the available bone width because it offers greater surface area, greater mechanical engagement of the cortical bone, and initial rigidity. Using a wide implant in a narrow ridge results in labial or lingual dehiscence that leaves the implant affected by the damaging shear stresses. 45
- 46. Number of implants… Mischstated that the use of more implants decreases the number of pontics and the associated mechanics and strains on the prosthesis, and dissipates stresses more effectively to the bone structure. It also increases the implant bone interface and improve the ability of the fixed restoration to withstand forces. Contrary to this Smith et al correlated between the increased number of implants and the high failure rate caused by wound contamination that might occur because of the long operating time. 46
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- 48. Excessive cantilevers… ……Used implant-supported prosthesis. ……MesialC. > Distal C……. …Cantilever extensions cause load magnification and overloading of the implant next to the cantilever extension, which in turn leads to bone loss …With occlusal forces acting on the cantilever, the implant becomes a fulcrum and is subjected to rotational forces Etiology : restorative facto 48
- 49. Not preferred ----moderateto severe parafunctional habits Opposing arch… …ideally a denture …no lateral forces on cantilever Amount of force increases if… …Length of cantilever …distance between implants …crown height …direction of force …position of arch Etiology : restorative facto 49
- 50. Connecting implants toteeth… Not preferred… Difference b/w implant & tooth movement in vertical & lateral direction Etiology : restorative facto 50
- 51. Solution… …… increase no.of implants …… improve stress distribution by splinting additional abutment until 0 clinical mobility is observed. …… non-rigid connection – but chances of intrusion of the tooth. Etiology : restorative facto Criteria… 1) no observable clinical mobility of natural abutment. 2) no lateral force should be designed on prosthesis. 51
- 52. Pier Abutments… Etiology :restorative facto Main complication d/t difference of mobility of tooth & implant …2 situations arise… Implant as pier Tooth as pier …Tooth act as living pontic or pontic with a root …stress breaker –not indicated Act as class 1 lever Non rigid attachment 52
- 53. One of themost critical elements affecting the long- term success of a multiple implant restoration is the passive fit between the framework and the underlying fixtures. A passive fit reduces long term stresses in the superstructure, implant components, and bone adjacent to the implants. A poorly fitting implant framework can cause mechanical complications such as loose screws or fractured components. No passive fit… Etiology : restorative facto 53
- 54. Improper fit ofabutment… Improper locking b/w abutment-fixture interface Increased microbial population & increased strain on implant component Bone loss Rapid screw-joint failure Etiology : restorative facto 54
- 55. Important guidelines tofollow • Infraocclusion upto 30 microns of implant supported restoration • No balancing contacts on cantilevers. • No guidance on single implants. • Freedom in centric. • Occlusal table directly proportional to implant diameter. • Narrow occlusal width. • Implant length: crown-root ratio ideal – 1:2 , Acceptable – 1:1 for removable denture. • Avoidance of cantilever length. Maximum 10 to 15 mm is advised. 7 mm is optimum . • Shallow central fossae with tripodal cuspal contacts. • No contact in lateral excursion. • Slight contact in centric occlusion. Etiology : restorative facto Improper occlusal scheme… 55
- 56. According to timingof failure Before stage II After stage II After restoration 56
- 57. Problem Possible causeSolutions Hemorrhage during drilling Lesion or injury of an artery -The implant placement will stop the bleeding. -Simple tamponade , bone wax, gelfoam , surgicel , avitene can also be used Implant mobility after placement Soft bone Imprecise preparation Remove the implant and replace with one of larger diameter. If the mobility is small prolong the healing time Exposed implant threads Too narrow crest Cover the threads with coagulum or place a membrane Swelling lingually directly after implant placement at the mandibular symphysis Incision of an artery branch sublingually EMERGENCY: send the patient to a specialist center for coagulation of the artery under general anesthesia First stage surgery 57
- 58. Injury to neurovascularbundle… The posterior mandible in particular presents significant challenge when severe atrophy leaves little, if any bone superior to inferior alveolar canal. …The solution to limited space for posterior mandible fixture placement includes detailed initial treatment planning and careful surgery to unroof the canal and move the neurovascular bundle inferiorly prior to fixture installation… 58
- 59. Problem Possible causesSolutions Slightly sensitive but perfectly immobile implant Imperfect osseointegration Cover the implant for 2-3 months and test again Slightly painful and mobile implant Lack of integration Remove the implant Difficulty inserting a transfer screw, gold screw or healing cap Damaged inner thread of abutment screw Change the abutment screw Inability to perfectly connect the abutment to the implant Insufficient bone milling Place a local anesthesia, use a bone mill with guide, remove the bone, clean with saline solution, and replace the abutment Granulation tissue around the implant head Traumatic placement of the implant; compression from the transition prosthesis; a lid above the cover screw Open the area and disinfect with chlorhexidine. If the lesion is too large, consider a bone regeneration or grafting technique Secondstagesurgery+ abutmentconnection 59
- 60. Problem Possiblecauses Solutions Painor sensation when tightening gold screws (during try in of prosthesis) Misfit between prosthesis and abutments Cut the prosthesis; interlock the pieces, and solder the prosthesis at the laboratory. Retry the prosthesis Loosening of one or more prosthetic screws at the first inspection after two week Occlusal problem Retighten, verify the occlusion, and recheck after two weeks. Prostheticproblems 60
- 61. Loosening of prosthetic screws atthe second check or later Occlusal problem or misfit between prosthesis and abutments Too large extension Unfavourable prosthetic concept Verify the occlusion and/ or the prosthetic fit Reduce the extension Change the prosthetic design. In all cases, change the prosthetic screws Fracture of a prosthetic screw or an abutment screw Occlusal problem, lack of fit between the prosthesis and the abutment or unfavourable prosthetic design If the occlusion or the adaptation of the prosthesis seems right, modify the prosthetic design (reduce or eliminate extensions, reduce the width of occlusal surfaces, reduce cuspal inclination, add implants, etc) Prostheticproblems 61
- 62. Fracture of the framework Weakmetal frame end or too large extension Bruxism or parafunction Remake the prosthesis; modify the prosthetic design (reduce or eliminate extensions, reduce width and height of occlusal surfaces, reduce cusp inclination, add implants, etc). Make a nightguard Implant fracture Occlusal overload Remove the implant with a special trephine drill, wait 2- 6 months, if possible, and place a wider implant. Review the prosthetic design(place more implants, etc) and remake the prosthesis Prostheticproblems 62
- 63. 1. Continuing bone lossaround one or more implants Infection (peri- implantitis) Remove the etiolgical factors (poor plaque control, prosthesis geometry in relation to the mucosa, etc). Look for bacterial pockets around the natural teeth. Possibly make a bacteria test. Cut open the lesion. Adjust the peri-implant tissues (gingival graft). Consider a bone regeneration procedure 2. Continuing bone loss around one or more implants Occlusal overload Modify the prosthetic design (reduce or eliminate extensions, reduce the width of occlusal surfaces, reduce cuspal inclination, add implants, etc) Prostheticproblems 63
- 64. Psychological Problems According to failuremode Lack of Osseointegration Unacceptable Aesthetics Functional Problems 64
- 65. Lack of Osseointegration…… Adellet al proposed that lack of osseointegration can be due to…… ……Surgical trauma ……Perforation through covering mucoperiosteum during healing ……Repeated overloading with microfractures of the bone at early stages Functional problems…… Proper function of the implants is dependent on two main types of anchorage related and prosthesis related. Anchorage related factor… Osseo integration Marginal bone height Prosthesis related factor… Prosthesis design Occlusal scheme 65
- 66. Aesthetic problem…… Aesthetic outcomeis affected by four factors: …Implant placement …Soft tissue management …Bone grafting consideration …Prosthetic consideration Psychological problems…… …high expectations of the patient 66
- 67. …Soft tissue problems …Boneloss …Both soft tissue and bone loss According to supporting tissue type…… 67
- 68. Soft tissue problems Gingivalloss leads to continuous recession around the implant with subsequent bone loss. This will lead to a soft tissue type of failure. Significance of attached gingiva surrounding implants …facilitates impression making. …provide tigth collar around the implant. …prevent recession of marginal gingiva. …prevent spread of inflammation to deep tissue. 68
- 69. Ono,Nevin,Cappetta classified keratinizedgingiva based on reflection of quantity & location in mucogingival surgery during implant placement…… Type 1- flap can be apically positioned to increase the zone of keratinized gingiva on facial side Type 2-minimum keratinized tissue on ridge but little on facial aspect Type 2 class I- gingival graft Type 2 class II- gingival graft on buccal side, Apically positioned flap on lingual site 69
- 70. Type 3- noattached gingiva on the ridge or facial aspect. A gingival graft which is apically postioned to increase the Zone of attched gingiva. 70
- 71. Bone loss Loss ofmarginal bone occurs both during the healing period and after abutment connection Bone loss in mandible is higher during the healing period. In maxilla, bone loss is higher after abutment connection Bone functions as a support for the implant and that any disturbance in its function may lead to eventual loss of the implant. 71
- 72. Factors that contributeto marginal bone loss: •Surgical trauma such as detachment of the periosteum and damage cased during drilling •Improper stress distribution caused by defective prosthetic design and occlusal trauma •Physiological ridge resorption •Gingivitis, which if allowed to progress will lead to ingression of bacteria and their toxins to the underlying osseous structures. Both soft tissue and bone loss If failure starts from soft tissue, then it usually is considered to be due to a bacterial factor. However, if failure starts at the bone level, then it is considered to be due to a mechanical factor. Both bone and soft tissue may be involved together. 72
- 73. Enhancing esthetic outcome inimplant dentistry… Prosthodontic considerations Surgical consideration Use of platelet–rich-plasma 73
- 74. Prosthodontic consideration… 1) Interimprovisional restoration: Resin bonded FPD Use of transitional implants to Support an interim provisional restoration Modified Essex retainer 74
- 75. 2) Prosthetic guidedsoft tissue healing: Custom abutment & tooth form restoration Custom tooth form healing abutment 75
- 76. Surgical consideration… Cosmetic lasersoft tissue resurfacing & sculpting Creating harmony with cosmetic PD surgery 76
- 77. Use of platelet-rich-plasma …Provideblood component & source of growth factor which enhance the wound healing …3-4ml of non-activated P-R-P is sufficient for multiple implant site Hard tissue consideration Soft tissue consideration Both …enhancing osseointegration …alveolar ridge preservation …in autogenous bone graft 77
- 78. Peri- implantitis Progressive peri-implantbone loss in conjunction with a soft tissue inflammatory lesion is termed peri- implantitis. Pathological changes of the peri-implant tissues can be placed in the general category of peri-implant disease. (Lang et al 1994) Two primary etiological factors 1. Bacterial infection 2. Biomechanical overload (Newman et al 1988, 1992, Rosenberg et al 1991) 78
- 79. Classification of peri-implantitis ClassI …Slight Horizontal bone loss with minimal Peri-implant defects. TREATMENT……Initial therapy for removal of etiological factors. …Surgical therapy includes cleaning the implant surface, Pocket elimination via Apicalpositioning of flap. Class II …Moderate horizontal bone loss with isolated vertical defects. TREATMENT …Initial therapy for removal of etiological factors …Surgical therapy includes cleaning the implant surface pocket …Elimination and adjunctive treatment using systemic antimicrobials 79
- 80. Class III Class IV Moderateto advanced horizontal bone loss with broad, circular bony defects. TREATMENT …Initial therapy for removal of etiological factors …Surgical therapy includes cleaningthe implant surface …pocket elimination via osseous regeneration and adjunctive antibiotic treatment Advanced horizontal bone loss with broad circumferential vertical defects as well as loss of buccal and lingual bony wall. TREATMENT .Initial therapy for removal of etiological factors .Surgical therapy includes cleaningthe implant surface,pocket elimination via bone regeneration techniques, possibly autologous bone transplants with adjunctive antibiotic therapy. 80
- 81. These are primarilyrelated to failure of prosthodontic materials to resist forces and stresses of oral function. Mechanical complications… 81
- 82. Fractured abutment screw Tipof the explorer is placed on the top portion of the fractured abutment screw. With slight apical pressure and a counterclockwise circular motion, the fragment can often be unscrewed. Care must be taken not to damage the internal threads of the implant. ……When Screw Fragment removed ,replace with appropriate new abutment and screw. Verify seating with a radiograph prior to final torque. ……Replace prosthesis and secure with new retention screws. 82
- 83. Radiographic evaluation ofa loose healing abutment. Removal of healing abutment indicates a distorted screw Treatment:Replace with new healing abutment Loose Healing Abutment 83
- 84. Area of concern Radiograph confirmspoor seating abutment. Diagnosis- possible loose or fractured abutment screw Clinical evaluation after removal of bar indicates loose abutment screw. Treatment:Retorque abutment screw. Loose bar… 84
- 85. Treatment: continued 2 - Abutmentscrew is tightened with abutment driver. 3 - Bar is then replaced and prosthetic screws are torqued with appropriate screw driver. 85
- 86. Loose restoration… Radiographic Evaluation:Small opening at abutment-implant interface Small opening Diagnosis:Loose abutment screw Treatment: 1 - Loosen screw and remove restoration 86
- 87. 2 - inspectthe implant hex for damage 3 - inspect the restoration for damage Implant hex Abutment hex (A) No Damage to fixture or restoration …replace restoration and secure with the same screw.Verify seating with radiograph prior to final torque.Recheck occlusion with shimstock. (B) Damaged fixture hex and or restoration replace restoration and secure with appropriate new screw. 87
- 88. Fixture loss (Must differentiateb/w “failing” and “failed”) Failing Implant Clinical signs:progressive bone loss :soft tissue pockets and crestal bone loss :bleeding on probing with possible purulence :tenderness to percussion or torque forces Causes:overheating of bone at the time of surgery or lack of initial stability. :inadequate screw joint closure :functional overload :periodontal infection (peri-implantitis) Treatment:Interim: remove prosthesis and abutments :irrigate with Peridex :ultrasonic and disinfect all components :reinsert assuring proper screw torque :recheck passive fit of framework and occlusion 88
- 89. Causes: :surgical compromise (overheatingbone and initial lack of stability). :Inadequate screw joint closure :Too rapid initial loading :Functional overload :Periodontal infection (“peri-implantitis”) Clinical signs: …Mobility…verify fixture mobility by removing any abutments and superstructures first. …A “Dull” percussion sound has been associated with a failed implant. …Peri-implant radiolucency can be a radiographic finding often this is not evident on an X-ray Failed Implant Treatment :removal of the implant 89
- 90. Treatment:Eventual implant removal Fracturedimplant fixture head 90
- 91. Accidental swallowing orinhalation of components and /or instruments Many implant components are as small as are the instruments used for their manipulation. When coated with saliva a component may escape the clinicians grip and fall into the oropharynx, reflex swallowing may take the component out of site almost immediately. Prevention Manual screwdrivers and similar instruments should always be equipped with a safety line of dental floss.(Minimum length of 10mm) 91
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- 93. …oral hygiene …implant stability(evaluate mobility) …peri-implant tissue health …crevicular probing depths …bleeding …radiographic assessment (serial) crestal bone level (expect 1.0mm marginal bone loss during first year postinsertion; 0.1mm per year anticipated thereafter ) …proper torque on screw joints …occlusion …Patient comfort and function The following factors must be evaluated at each maintenance appointment…… 93
- 94. Hygiene aids…… Super -floss End tufted brushes Proxy brushes Tartar control dentrifices Mechanical instruments 94
- 95. Super - Floss Excellentfor all types of implant restorations Butler Post Care Floss Aid Excellent for implant bars and fixed hybrid prostheses. 95
- 96. Butler Floss Aidis used to clean the bar including the area contacting the tissue. 96
- 97. End tufted brushes Proxybrushes 97
- 98. Plastic scalers are appropriatefor cleaning around standard abutments supporting implant bar substructures, hybrid prostheses and implant supported splinted restorations. Plastic scaler tips are also available for metal handle scalers. Plastic scalers… 98
- 99. Implant supported fixed partial denture Scalertips are designed to fit the curvature of the standard abutment. 99
- 100. Prophy paste anda rubber cup on a prophy head / handpiece can be used to polish implant bars when removal is not indicated 100
- 101. Failure of implanthas a multi-factorial dimension. Often many factors come together to cause the ultimate failure of the implant. One needs to identify the cause not just to treat the present condition but also as a learning experience for future treatments. Proper data collection, patient feedback, and accurate diagnostic tool will help point out the reason for failure. An early intervention is always possible if regular check-up are undertaken. As someone well said, it is not how much success we obtain, but how best we tackle complex situations and failures, that determine the skill of a clinician. No, doubt, failures are stepping stones to success but not until their etiologies are established and their occurrence is prevented. Conclusion… 101
- 102. Misch : Contemporaryimplant dentistry Atlas of implant dentistry, Cranin Why do dental implants fail: part I : Askary et al ID 1999 vol8 no2 173-183 Why do dental implants fail: part II : Askary et al Id 1999 vol 3 : 265-275 A.S.Sclar; Soft tissue & esthetic considerations in implant dentistry. Myron Nevins; Implant therapy. Torosian J, Rosenberg ES. The failing and failed implant: a clinical, microbiologic, and treatment review. J Esthet Dent. 1993. Failures in implant dentistry.W. Chee and S. Jivraj. British Dental Journal 202, 123 - 129 (2007) REFERENCES 102
- 103. Yoav Grossmann. Prosthetictreatment for severely misaligned implants: A clinical report. J Prosthet Dent 2002;88:259-6. Goodacre C J, Bernal G, Rungcharassaeng K, Kan J Y. Clinical complications with implants and implant prostheses. J ProsthetDent 2003; 90: 121–132. Effect of implant size and shape on implant success rates: A Literature review JPD 2005;94:377-81 WWW.google.com 103
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Editor's Notes
- #6 This saying is also applicable to implnt failure